Question for USB3.0Test has stopped working with USB3.0 Loopback Plugs.

[sunnyyang]

Dear Sir,

We had modified De-emphasis register of DUT to meet the eye mask request, but this modification made us encountered USB3.0 test halted with USB3.0 Loopback Plugs as below.


We found the issue will not happen if the eye voltage swing is over 500mV..

Could you help to confirm the USB3.0 voltage swing output of DUT should be over 500mV for USB3.0 Loopback Plugs detected?

Best regards,
Sunny Yang

[HamidK (PassMark)]

We checked the documents provided by the USB chip manufacturer, but we couldn't find the minimum required swing voltage on the RX pins. FYI, we are using Cypress FX3 chip in USB3 plugs. So you might want to contact Cypress if you need additional technical details.